This application seeks support for the acquisition of a Hologic Model QDR 2000plus Whole Body X-Ray Bone Densitometer DEXA with ODS-2 Optical Disk Storage Module and BCA-1 Body Composition Analysis Software. This instrument will markedly enhance the precision and the reliability of nutrition related research involving body composition measurement at Harbor-UCLA Medical Center. This DEXA instrument accurately measures bone density, cross sectional bone area, total body fat, and, by subtraction, lean body mass. Acquisition of this instrument will enable a number of NIH funded investigators at Harbor-UCLA Medical Center to maintain state- of-the-art technology for assessing nutritional status and the response to nutritional intervention.